Tool



Jan. 24, 1928. A. NIEDHAMMER TOOL Filed Oct, 1. 1925 2 Sheets-$heet 1 ln veh'tOT; Adam Nledhammer,

MXM

His A-t-torneg.

Patented Jan. 24, 1928.

PATENT OFFICE.-

ADAM mnnrmmma, or scnnnncranr, NEW YORK.

moon Application filed October The present invention relates to a tool for driving screws, nuts, bolts and the like and has for its object the provision of an improved device of this character which oh- 2 viates the need heretofore experienced with such tools, of a separate tightening or setting operation following the driving operation by the tool.

The tool of the present invention performs in the final setting operation automatically in continuation of the driving operation and provides for easy adjustment of the force applied in the setting operation.

For a further consideration of what is bem lieved to be novel and the invention, attention is now directed to the accompanying drawings, the description thereof and the appended claims.

In the drawings, Fig. 1 1s a sectional side view of a tool embodying the invention,

showing the relation of certain parts thereof during the initial driving operation, and Fig. 2 is a similar view of said tool, partly in sect-ion, showing the relation of said parts 25 at the end of the setting operation; Fig; 3 is a sectional view taken on line 33.of Fig. 2; Fig. 4 is a detail view in perspective of certain parts taken from the tool of Figs. 1 and 2; Fig. 5 is a detail of a modification of 3B certain parts applicable to the tool of Figs.

1 and 2; Fig. 6 is a side view, partly in sec-v tion, of a modification of the tool shown in Figs. 1 and 2; Fig. 7 is a detail view of a part thereof; and Fig. 8 is a view similar to Fig. 6 of a further modification.

Referring'to Figs. 1 to 5 inclusive, 10 is a cylindrical driving member or head having an axially extending shank or drive shaft 11 integral therewith at one end and a shallow counterbore 12 at the opposite end in which is located a cylindrical face plate 13 integral and coaxial with a tubular driven member or tool chuck 14.

The driving head and chuck are rotatable with respect to each other and are maintained in coaxial alignment by guide hearing means comprising a hollow guide stud or pin 15 integral with and in axial extension all of the chuck and a ring bearing 16 in which I the pin is provided with a smooth running lit. The ring bearing is located in the lower end of a counterbore 17 which communicates 1, 1925. Serial No. 59,987.

with counterbore 12 and extends axially through the driving head and shaft to a point adjacent the upper end of the latter.

The face plate fits loosely in the counterbore 12 and is retained therein by a thrust washer or bearing member 18 of fibre, textolite or similar material. The latter lies about the chuck and is clamped between the lower end of the driving head and the bottom wall of a retaining cap 19. The retaining cap is screwed on to the driving head as indicated at 20 and draws the thrust washer to a seated position over the counterbore 12 and the lower end of the driving head. The retaining cap is provided with an annular knurled ring 21 integral therewith by which it may be turned in drawing the thrust ring to a seated position. A central clearance opening 22 for the tool holder is provided in the bottom wall of the retaining cap.

The hollow interior of the chuck is adapted to receive interchangeably various tools for driving different types of screw-threaded objects, such as bolts, screws and the like, and in the present example is provided with a cylindrical socket wrench 23 for driving bolts of the type indicated at 24. The tools are retained in the chuck by a removable flat pin 25 which passes through and lies in aligned slots 26 and 27 in the chuck and the tool respectively. The slots are slightly wider than the' retaining pin so that the tool is movable axially in the chuck .a short 85 distance. When' engaged with a bolt or other object to be driven, the tool holder is moved to the upper limit of its travel as shown in Figs. 1 and 2.

The ends of the retaining pin extend slightly beyond the confines of slots 26 and are provided with shallow notches 28. A spring clip or retaining ring 29, which tightly encircles the chuck, is slipped upwardly into the notches to retain the pin in place. The tool is thus securely held in the socket of the chuck and may be quickly re.- moved by slipping the spring clip down onto the chuck body and withdrawing the retain-' ing pin.

The upper end of the driving member, that is the upper end of the drive shaft 11, is provided with a plurality of radial notches 30, there being four in the present example,

with which engage a corresponding number of clutch teeth 31 formed on the lower end of an adapter nut 32. The adapter nut is coaxial with the drive shaft and is connected with the latter by an axially movable guide rod 33 which lies in the counterbore 17 and extends therefrom through a central guide opening 34 in the end of the drive shaft into engagement with the adapted nut. In the present example the guide rod is provided by an elongated cap screw, the threaded end of which is screwed into a threaded axial socket 35 in the adapter nut, while the head 36 thereof is provided with a loose sliding fit in the counterbore.

The clutch teeth 31 on adapter nut 32 are normally engaged with notches 30in the end of drive shaft 11, as shown in Fig. 1, by a helical clutch spring 37 which lies about guide rod or bolt 33 in counterbore 1 and which is compressed between the bolt head and the upper end of the counterbore'. The sprin action is transmitted to the adapter nut tfilOllgll the medium of the bolt which also serves to maintain the said adapted nut in coaxial alignment with the driving member, that is with drive shaft 11 and the driving head 10. Q

It will be seen that the above-descr bed arrangement provides a normally closed spring clutch at the up er end of the drive shaft, the adapter nut orming one member thereof and the notched upper end of the drive shaft forming the other member thereof. The strength of' the clutch spring is such that the clutch members will be maintained in full engagement when, in operation, the entire device is suspended from theadapter nut, as shown in Fig. 1.

The adapter nut is provided with a threaded axial extension 38 at itsupper end by which it is connected with any suitable driving means. In the present exam le, a vertical drill-press chuck 39 is provi ed as a driving means. The chuck is of the usual tapered socket type which is axially movable while rotating, and connection is made therewith through a correspondingly tapered arbor 40 threaded onto the adapter nut and forced into frictional enga ement with the chuck. As this form of riving means for tools is well known and as it re resents any suitable driving means for t e tool or device of the present example, further description thereof is believed to be unnecessar The relatively rotatable driving and driven members, that is, driving head 10 and chuck 14 are releasably connected together by, and 1n the present example form art of, a normally closed clutch means w ich is arranged to permit the members to slip or rotate with respect to each other when a certain retardin force is applied to the driven member. he arrangement is such nee-mu that the slipping is accompanied by a hammerin actlon on the drlven member, the intenslty of which may be adjusted and by which said member is slowly advanced in opposition to the force as the driving member rotates.

This arrangement, as provided in the present example, comprises four equally spaced slots or grooves 41 in the upper face of face plate 13 with which engage four cylindrical plungeis or clutch teeth 42 having detachable spherical or curved ends 43, which seat in the grooves.

The plungers are slidably mounted in axially arallel relation to each other in driving ead 10 in guide holes or bearings 44 which are equally spaced about the axis of rotation of said heads, each in registration with one of the grooves in the face plate. The bearings extend from the inner face of counterbore 12 through the upper end of the driving head and are of such length that the plungers are properly guided therein, the desired bearin length bein obtained by providing a drivlng head of t e proper thickness. The upper ends of the plungers lie flush with the upper ends of the bearings and lightly engage with a flat ring or spring seat 45 when their lower spherical ends 43 are fully seated in the face plate grooves, as indicated in Fig. 1.

A relatively heavy compressed helical spring or clutch spring 46 surrounds the .drive shaft and forces the spring seat against the upper end of the driving head and into contact with the plunger ends. The drive shaft is threaded, as indicated at 11, to re ceive a spring adjustment or hand nut 47, by which the force exerted by the spring is adjusted to any desired 'value. The hand nut is provided with a knurled flange 48 by which it is turned and is counterbored on its lower face to receive a fiat ring or spring follower 49. The latter surrounds the drive shaft and is moved by the hand nut to compress the spring against which it bears. The sprin follower is prevented from turning with the hand nut by an inte ral key 50 which loosely engages in an axiadly extending keyway 51 in the drive shaft.

. A locking means for the hand nut to hold it in position when the spring is properly adjusted is provided by a lockin pin 52 which lies in a curved slot 53 in ange 48 and which is adapted to enter any one of a series of spaced holes 54 in the spring follower, as shown in Figs. 1 and 3. One end of slot 53 is so located that it registers successively with holes 54 as the adjustment nut is turned, while the opposite end of the slot lies out of registration with said holes. The pin is carried on one end of a spring arm 55, the opposite end of which is pivotally secured to the flange by a screw 56.

The arm is movable on the screw as a .vide plungersprovide a driving connection bepivot to carry the pin along the slot. When an adjustment is made the pin is lifted from the hole in which it is seated by lifting the adjacent spring end-and is moved to the outer end of the slot so that it clears holes 54 in the spring follower and slides along the top of thelatter as the adjustment nut is turned. When the desired adjustment is secured, arm 55 is moved to carry the pin to the opposite end of the slot. and the adjustment nut is then turned in the direction of the nearest hole 54 until the'pin registers and snaps into engagement therewith under the action of the spring arm.

It will be seen from the foregoing that clutch spring 46 forms a common adjustable means for resiliently maintaining the slidabl mounted plungers 42 in engagement witthe grooves 41, being connected with said plun ers by a common equalizer means proby the ring or spring seat 45. The

I tween the driving head and the driven chuck 14, and transmit the driving force from the former to the latter by engagement with the grooves 41. The plunger ends 43 which engage the ooves are detachable as hereinbefore state being in the form of balls seated in central end sockets 57 in the plungers, although said ends may be integral with the plungers, as shown in connection with plunger 42' in Fig. 5. The

rooves 41 are curved on equal radii about lue axis of rotation, as indicated in Fig. 4, and lie in spaced end to end relation with each other. They are also provided with curved side and end walls to conform in shape to the plunger ends and are of a depth equal to slightly less than one-half the diameter of the plungers, that is, they have a depth slightly less than the radius of the spherical ends 43. This arrangement provides for permitting the plungers to slip from groove'to groove when a certain retarding force is applied to the chuck, as it is driven by the driving head 10.

When slipping occurs the plungers are moved axially against spring seat 45 and the adjusted b compression -force of spring 46 as the spherical ends thereof move upwardly on the curved ends of the grooves and out of the latter on to lands or flats 58 which separate the ends of the grooves; The plungers, carried by the driving head, slide along the lands until they meet and snap into the next grooves ahead in the direction of rotation. The slipping continues while the retarding force is sufiicient to cause the plungers to leave the grooves. v

The force required to cause slipping is adjusting the hand nut 47 to compress t e helical spring 46 to a greater or lesser degree, thereby holding the plunger ers seated in the grooves witha greater or lesser force as the casemay be. The thrust of the plungers and the axial com onent of the hammer blows delivered there y on the face plate is met by the thrust washer 18 which lies beneath it. To rovide a slightly resilient cushion beneath the face plate, the washer is preferably of textolite.

The grooves are elongated in the direction of rotation and curved on equal radii, as hereinbefore stated, so that relative rotative movement is permitted between the driving head and the chuck while the plungers are engaged with the grooves. It will be seen that this arrangement provides for continued slipping after the plungers enter the next grooves ahead in the direction of rotation, terminating in a shock or hammer blow as the plungers meet the opposite ends of the grooves.

While, in the present example, four plungers or clutch teeth and four rooves are provided, it will be appreciated that any suitable number of plungers and grooves may be employed, although at least two of each are desira 1e. In this connection it may be said that the number of plungers and grooves is" such that a driving connection is provided between the driving head and chuck of sufficient strength to transmit the normal driving force and to withstand the hammer-blow action when slipping occurs.

In the present exam Ie the grooves are equally spaced, as herembefore stated, and are of equal length whereb the equally spaced plungers move out o and into the grooves simultaneously when slipping occurs, and meet corresponding ends of the grooves simultaneously after the manner indicated in Fig. 4. The hammer blows of the plungers against said ends of the grooves are therefore delivered simultaneously in the arrangement shown. The invention is not limited to this particular arrangement, however, as any other suitable arrangement and spacing of the plungers or clutch teeth and the grooves may be provided to deliver a series of hammer blows to the driven member as slipping occurs.

The operation of the tool is as follows: The tool is connected with a rotating driving means such as the drill-presschuck 39 through the medium of the adapter nut 32 and arbor 40, preferably in a suspended position as shown; and the socket wrench 23 is moved with the tool down over'the head of the bolt 24 which is to be driven. The clutch teeth 31 on adapter nut 32 are engaged with the notches 30 on the drive shaft and the plungers 42 are engaged with the grooves 41, as shown in Fig. 1. The drivin force is thus directl transmitted from the driving means throng the tool to the bolt 24.

The direction of rotation of the drivin means depends upon the direction in whic the bolt or other device is to be driven. In the present example an ordinary right-hand threaded bolt is shown; therefore the drillress chuck and tool are rotated in a. rightand direction. In this case also the axial extension 38 on the adapter nut 32, the retaining cap 19 and the driving head 10 at 20 are provided with corresponding righthand threads so that in operation the thread ed connections formed thereby remain tight. The above-mentioned parts of the tool are therefore preferably threaded to correspond in direction to the threads on the object to be driven.

When the tool engages the bolt, the latter is rotated to a seated position as the tool rotates. The tool is moved to follow the bolt and maintain engagement therewith. As the bolt reaches a seated position, a retarding force is increasingly applied to the tool with a result that the clutch teeth or plungers 42 are forced out of the grooves and slipping occurs. The plungers are carried by the driving head at an undiminished speed and in slipping impart a rapid series of hammer blows to the forward ends of the grooves, thus forcing the chuck, wrench and bolt connected therewith, ahead at a slower speed in a series of steps. The bolt is in this manner hammered to a tightly seated position, the ti htness of which is determined by the justment of the hand nut 47 which controls the force with which the plungers or clutch teeth are held in the grooves.

The proper adjustment for the hand nut is determined by trial with the first bolt or object driven and is such that after being seated by the tool said bolt or other object cannot be further tightened by the usual manual means and that the threads thereon are stressed well below the point at which stripping might occur. When the tool is properly adjusted, it is maintained in engagement with thebolt or other object bemg driven until continued slipping of the plungers efiects no appreciable turning movement thereof. The tool is then withdrawn from the bolt.

Bolts driven by a socket wrench, after the manner shown in the present example, tend to remain in frictional engagement with the socket thereof when it is attempted to withdraw said tool. 'It has been found that under thiscondition the tool may be easily withdrawn if it is disconnected from the driving means.

In the present example means for automatically disconnecting the driving means is provided by the clutch means at the upper end of the drive shaft 11 which is opened against the action of sprin 37 when the tool is held in engagement with thebolt 24, while the drill-press chuck is moved in a direction to withdraw the tool. This action is indicated in Fig. 2, the clutch being fully disengaged to permit the driving means to rotate while the tool remains stationary.

Beveled ed es are provided on one of the clutch mem ers, as indicated at 59, Fig. 3 to permit easy reengagement after the tool has been withdrawn from the seated bolt.

' This clutch means also rovides a safety means for stopping the riving operation at any time by iftmg the drill-press chuck and tool from the bolt. If the tool sticks on the bolt, the clutch means is opened by the lifting action, and the tool remains inoperative while the drill-press chuck is held in the lifted position.

In Fig. 2 it will be noted that the plun ers 42 are disengaged from grooves 41 an in contact with the flats or lands 58 between the grooves, being in the act of advancing to reengage with the grooves ahead in the direction of rotation as the tool holder is retarded by the seated bolt 24. The latter is being advanced to a fully seated position by the hammering action following each reengagement of the plungers with the grooves. Also in connection with Fig. 2 it will be noted that with the plungers withdrawn from the grooves, the spherical ends 43 thereof are wholly enclosed and carried by the guide holes 44, while in Fig. 1 said spherical ends lie partly in the guide holes and partly in the grooves to form the connection between the driving head and the driven tool holder. This connection may be carried out by other suitable plun er means, as indicated at 60 in Fig. 6 an at 61 in Fig. 8, to which figures attention is now directed.

In Figs. 6 and 8, the tool construction throughout is substantially identical with that of Figs. 1 and 2 and like parts throughout are accordingly desi ated by the same reference numerals. In ig. 6 the plungers 60 are spheres or balls which bear directly against the spring seat 45 and lie in guide .holes 44 in the driving head 10. In order that the plungers 60 may directly engage the spring seat 45' and the grooves 41 to form the. driving connection, the driving head 10 is correspondingly thinned and the guide holes or bearings 44 are shortened as compared with those of Figs. 1 and 2.

In this modification the spherical plungers are provided with shallow spherical seats 62 in the spring seat 45, as indicated in Fig. 7. The operation of the tool provided with spherical plungers is the same as that of Figs. 1 and 2 and is believed to require no further description.

In certain applications of the tool, for ex ample where greater driving force with less sprmg pressure is desired, the spherical plungers may be provided with fiat upper ends whereby they are limited to sliding action into and out of the grooves. Plungers 61 of Fig. 8 are of this type and otherwise operate the same as plungers 60.

A tool is connected with a source of driving power throu h a clutcli means which automatically rel moved away from the work, tends to remain engaged therewith, and that the driven member connected with the driving member by a second clutch means which is provided I with slots or grooves with which engage resilient clutch teeth or plunge the engagin force of which may be adj uste The clutc teeth and grooves are shaped to permit slipping between the driving'and driven memrs accompanied by a hammering action when a certain retarding force is met by the driven member. It is obvious that in carrying out this arrangement other means than that shown may be employed without departing from the spirit and scope of the invention.

What I calim as new and desire to secure by Letters Patent of the United States is:

1. In a device of the character described,

the combination of a rotatable driving member, a driven member coaxial therewith, and a clutch means connecting said members, said means comprising a plurality of clutch teeth resiliently mounted in one of saidmembers and elongated slots in the other member with which the clutch teeth engage, said slots being elongated in the direction ofrotation and curved in equal radii about the axis of rotation of the driving member, said slots having curved end walls which conform in shape to the ends of the clutch teeth. 2. In a tool of the character described, a rotatable driving member, a driven member coaxial therewith, a clutch plate carried by the last-named member, a plurality of elongated spaced slots in the clutch plate, springpressed means carried by the driven member for resiliently engaging said slots, said means having ends which lie in said slots and said slots being elongated in the direction of rotation and curved on equal radii about the axis of rotation of the driving member, said slots having curved end walls which conform in shape to the ends of said-spring-pressed means, and means providing a ide bearing between said members by which they are held in coaxial relation.

3. In a tool of the character described, a rotatable driving member a driven member coam al therewith, a clutch plate carried'by the last-named member a plurality of elongated spaced slots in the clutch plate, said slots bein elongated in the direction of rotation and curved on equal radii about the axis of rotation of the driving member, spring-pressed means carried by the driven cases when the tool, on being b member engaging said slots, means providmg a guide bearin between said members by which they are old in coaxial relation, and a thrust bearing means for the clutch plate for meeting thethrust of said springpressed means.

4. In a device of the character described,

the combination of a rotatable driving memr, a driven member 'ournaled therein to rotate coaxially therewith, a face plate carried by the driven member, a pluralit of spaced elongated grooves in the face p ate, a plurality of clutch teeth carried by the driving member in alignment with the grooves, said clutch teeth being movable into and out of said grooves, and said grooves being elongated in the direction ofrotation and curved on equal radii about the axis of rotation of the driving member whereby relative rotational movement of the driving and driven members is permitted while said clutch teeth are seated in said grooves, and adjustable spring means connected with said clutch teeth for resiliently retaining them in the grooves, said grooves having end walls which conform in shape to the ends of the clutch teeth whereby when the. latter are moved to meet the end walls of the ooves an abrupt hammer blow is delivered y each 5. In a tool of the character described, the combination of a cylindrical drivin head having a threaded drive shaft integrall therewith at one end and an axial counterbore at the opposite-end, said driving head and shaft being coaxial, a tool chuck coaxial with the driving head, a guide bearing means between the driving head and the chuck by which they are maintained in coaxial relation, a face plate coaxial with the tool chuck seated in said axial counterbore in the driving head, means providing a thrust bearing for holding the race late in the counterbored driving head, a p urality of elongated grooves in the face plate adjacent the bottom of the counterbore, said grooves being arranged in spaced end to end relation with each other and curved on equal radii about the axis of rotation, a p urality of clutch teeth carried by the driving head, said clutch teeth being aligned with the grooves and slidably mounted to move into and out of engagement therewith, a fiat ring surrounding the drive shaft and engaging the clutch teeth, a spring surrounding the drive shaft and seated against the ring, and means for adjustably compressing the spring against said ring to hold the clutch teeth in engagement with the grooves.

6. In a device of the character described,

- the combination of a rotatable driving memher, a rotatable driven member coaxial therewith, and driving means connecting said members, said means comprising a pluralit of resilientl mounted plungers carried y one of sai. members, and elongated slots in the other member through which the plungers are adapted to move freely and with the ends of which said plungers are adapted to strike in operatlon and deliver an abrupt hammer blow.

the plungers are adapted to move freely and with the ends of which said plungers are adapted to enga e in operation with an abrupt hammer blow, the ends of the slots being shaped to conform in she e to the plunger ends, and each of said s ots being of such depth that the plungers are permitted to move therefrom and advance to another after striking the hammer blow at ,,the end thereof.

8. In a device of the character described, the combination of a rotatable driving memher, a rotatable driven member coaxlal therewith, and means connecting said members which imparts to the driven member when retarded in'rotation a succession of hammer blows from the drivingh member in the direction of rotation of t e latter, said means comprising a fplurality of curved elongated slots in one 0 said members arranged about the axis of rotation of said members in e uall spaced relation thereto and in ace end -to-end relation to each other, a p urality of plungers carried by the other member and resiliently .pressed into engagement with said slots, each of said plun ers being movable with the last-named mem er alon said slots and being adapted to strike the s ot ends and deliver an abrupt hammer blow and to move thereover out of each slot and advance into engagement with a succeeding slot.

9. In a tool for driving and setting bolts, nuts and the like, the combination of. a rotatable driving member, a rotatable driven member coaxial therewith, the rotation of which driven member is retarded in operation by the setting of such bolts, nuts and the like, means connecting said members which transmits from the driving member to the driven member a succession of hammer blows when in o eration the driven member is retarded, sald means com rising a plurality of resiliently mounted p ungers carried by one of said members, a plurality of elongated spaced slots in the other member into engagement with which the plungers are resiliently pressed and along the length of which said plungers are freely movab e, the slots being of such depth that the plungers strike the ends thereof in operation and deliver an abrupt hammer blow, and the ends of said slots being shaped to move the plungers out of the slots after delivering such hammer blow, and means connected with the plungers for adjusting the resilient pressure thereon tending to hold them in engagement with the slots.

10. In a tool for driving and setting' bolts, nuts and the like, the combination of a rotatable driving member, a driven member, said members normally moving as a unit but being adapted to rotate relatively to each other, a plunger carried by one of said members and resiliently pressed into engagement with the other to form a driving connection therewith, said plunger being spaced from the axis of rotation of its carrying member whereby it is adapted to follow a circular path in engagement with the other member when said members rotate relatively to each other, means on said other member providing alternate lands and elongated grooves in the path of the lunger whereby the plunger moves alternate y into and along a groove and from the groove over a land when said relative rotation of the members occurs, said grooves having abrupt ends with which the plunger engages with an abrupt hammer blow at the termination of its passage through a groove.

11. In a tool of the character described, a pair of coaxial, rotatable driving and driven members and means carried jointl by said members for imparting a series 0 hammer blows from the driving member to the driven member in the direction of rotation when the latter is retarded in operation, said means comprising a plurality of plun ers carried by one member and resilient y pressed into engagement with the other, a plurality of spaced grooves in the other member for receiving the lunger ends, said grooves being elongated in a direction to permit the plungers to slide freely along the grooves and the latter having and walls adapted to receive a hammer blow from each plunger following the termination of its passage throu h the cove.

12. In a too for driving and settin bolts, nuts and the like, the combinationo a rotatable driving member, a normally closed sprmg clutch connected with the driving member, said clutch being adapted to open whena part thereof is retracted axially with respect to and from the driving member, a rotatable driven member coaxial with said dr1v1ng member, said members being adapt ed to rotate relatively to each other, a plunger which is carried by one member in spaced relation to the axis of rotation, said plunger being resiliently pressedinto enga ement with the other member and being t ereby' adapted to follow a circular path in engagement with said other member when the memoccurs, said grooves having abrupt ends with ADAM NIEDHAMMER.

bers rotate with respect to each other, means which the plunger engages with a hammer on said other member providin alternate blow at the termination of its passage lands and elongated grooves in t e path of through a groove. 7 10 the plunger, whereby the plunger moves In witness whereof, I have hereunto set 5 alternately through a groove and over a land my hand this 29th day of September, 1925.

when said relative rotation oi the members a 

